---

Developments in the oil contracts of countries indicate that most countries have abandoned the use of service contracts only and resorted to the contract model of production sharing contracts and new concessions, or by modifying, have driven their contract models to a variety of partnership contracts. However, this study shows that although many legal efforts have been made in Iran and Iraq to use this contract model, but the lack of clear law in this regard has led to the reform process of oil contracts leading to the implementation of models of long-term service contracts. The results of comparing the economic evaluation of Iranian petroleum contracts with service contracts and production sharing contract in Iraq show that the production sharing contract has higher economic efficiency, while creating the necessary incentives for the contractor to implement risky projects, in various economic conditions creates greater alignment between the interests of the parties to the contract, establishes a more efficient and equitable distribution of technical and economic risks between them, which is an important factor for the commitment of the parties to the implementation and termination of the contract. Therefore, it seems that due to the prevailing conditions in the oil market, including competition and declining trends in oil prices the use of the contract model of production sharing contract, at least for fields with difficult conditions and common fields, is a solution, but to use it like other countries, more effective legal measures such as the enactment of a law is essential.